This invention relates to an ergonomic adjustable chair and more particularly to an ergonomic adjustable chair wherein the occupant can move between a resting position and an extended position.
Much attention has been paid to the proper positioning and maintenance of the human body in a seated position. The patent literature discloses numerous seating devices directed to achieve various ergonomic objectives. For example, U.S. Pat. Nos. 482,745, 488,707 and 491,098 teach barber and dental chairs having integral foot supports. U.S. Pat. No. 4,369,997 discloses an articulated chair having an elevated seat surface and footrest. In U.S. Pat. No. 4,369,997, a seat surface and an interconnected footrest and a backrest may be adjusted from a position in which the seat surface is almost horizontal to an inclined position where the seat surface functions as a standing rest. U.S. Pat. No. 5,098,160 issued to Moore et al. describes a structure for adjustably positioning a footrest relative to an office chair.
While the foregoing seating and support devices provide ergonomic seating in various task specific applications, none of the seating and support devices found in the prior art provide a means to allow an occupant to stretch into an extended position and thereby stretch and exercise major muscle groups while staying in a generally seated position. Further, the prior art does not provide a way to actively support the lower back while the occupant shifts or changes his or her position.
The ergonomic chair of the present invention provides a seating system that allows the occupant, while seated, to shift his or her position while exercising major muscle groups and while benefiting from continuous lower back support. The ergonomic chair of the present invention includes a base and a seat support frame that supports a seatrest and a backrest. The seatrest and the backrest as connected so that they can pivot relative to each other. The backrest of the chair is slidably mounted to a pair of backrest tracks that are mounted to the seat support frame. The backrest is slidably mounted to the backrest tracks so that it can move along the backrest tracks between a lower resting position and a higher extended position. The seatrest which is hinged to the backrest slides and rotates relative to the seat support frame when the backrest is moved into the extended position.
The ergonomic chair of the present invention provides a seating system that allows the occupant, while seated, to shift his or her position while exercising major muscle groups and while benefiting from continuous lower back support. The ergonomic chair of the present invention includes a base and a seat support frame that supports a seatrest and a backrest. The seatrest and the backrest as connected so that they can pivot relative to each other. The backrest of the chair is slidably mounted to a pair of backrest tracks that are mounted to the seat support frame. The backrest is slidably mounted to the backrest tracks so that it can move along the backrest tracks between a lower resting position and a higher extended position. The seatrest which is hinged to the backrest slides and rotates relative to the seat support frame when the backrest is moved into the extended position.
With the addition of a footrest that is rigidly attached to the seat support frame, an occupant of the chair can push against the footrest and translate the backrest and the seatrest from a resting position into an extended position. After pushing up into an extended position, the occupant can by relaxing pressure against the footrest, allow the backrest and the seatrest to return to the resting position.
When an occupant is seated in a chair of the present invention having a properly located footrest, the stress placed on the lower back of the occupant as a result of being seated for a long period of time is greatly reduced. The occupant can stretch and exercise as described above. The chair of the present invention is also designed so that the backrest can provide constant lower back support even when the backrest is being translated into the extended position. The chair of the present invention even provides lower back support even when the occupant shifts or changes position.